Mineralisation of fibrillar collagen with biomimetic process-directing agents has enabled scientists to gain insight into the potential mechanisms involved in intrafibrillar mineralisation. Here, by using polycation- and polyanion-directed intrafibrillar mineralisation, we challenge the popular paradigm that electrostatic attraction is solely responsible for polyelectrolyte-directed intrafibrillar mineralisation. Because there is no difference when a polycationic or a polyanionic electrolyte is used to direct collagen mineralisation, we argue that additional types of long-range non-electrostatic interactions are responsible for intrafibrillar mineralisation. Molecular dynamics simulations of collagen structures in the presence of extrafibrillar polyelectrolytes show that the outward movement of ions and intrafibrillar water through the collagen surface occurs irrespective of the charges of polyelectrolytes, resulting in the experimentally verifiable contraction of the collagen structures. The need to balance electroneutrality and osmotic equilibrium simultaneously to establish Gibbs-Donnan equilibrium in a polyelectrolyte-directed mineralisation system establishes a new model for collagen intrafibrillar mineralisation that supplements existing collagen mineralisation mechanisms.

We report ultrahigh dielectric and piezoelectric properties in BaTiO3-xBaSnO3 ceramics at its quasi-quadruple point, a point where four phases (Cubic-Tetragonal-Orthorhombic-Rhombohedral) nearly coexist together in the temperature-composition phase diagram. At this point, dielectric permittivity reaches ∼ 75000, a 6-7-fold increase compared with that of pure BaTiO3 at its Curie point; the piezoelectric coefficient d33 reaches 697 pC/N, 5 times higher than that of pure BaTiO3. Also, a quasi-quadruple point system exhibits double morphotropic phase boundaries, which can be used to reduce the temperature and composition sensitivity of its high piezoelectric properties. A Landau-Devonshire model shows that four-phase coexisting leading to minimizing energy barriers for both polarization rotation and extension might be the origin of giant dielectric and piezoelectric properties around this point.

Owing to its excellent semiconducting and photoelectronic properties, [1] TiO 2 has recently attracted a great deal of interest for a large variety of applications. Examples include the use of TiO 2 nanoparticles/films as photocatalysts for environment protection, [2] photoelectron mediators for sensors, [3] photosensitizers in light-emitting devices, [4] and solar cells.[5]With the recent development in nanoscience and nanotechnology, there is now a pressing need to integrate multicomponent nanoscale entities into multifunctional materials and devices. [6] In this regard, TiO 2 nanoparticles have been deposited onto various catalytic supports to improve their photocatalytic activities. [7] In particular, activated carbon fibers and spheres were used as a class of chemically stable mesoporous catalytic supports to provide multiple active sites and to allow effective diffusion of reactants for the photocatalytic reactions.[8]Because of their unique one-dimensional electronic structure, large surface area, good chemical and thermal stability, and excellent mechanical properties, [9] carbon nanotubes (CNTs) may work better than other carbon forms to support TiO 2 for a wide range of applications, especially in photocatalytic and optoelectronic systems. As a consequence, some recent attempts have been made to coat nonaligned multiwalled CNTs with TiO 2 thin films, [10] whilst several synthetic routes were devised to prepare nonaligned TiO 2 nanotubes, [11] nanowires, or nanomembranes. [12] It will be a significant advantage if we can coat vertically aligned CNTs (VACNTs) with TiO 2 as the coaxial structure should allow the nanotube framework to provide a good mechanical stability, high thermal/electrical conductivity, and large surface/interface area necessary for efficient optoelectronic and sensing devices. [13] The alignment structure will also facilitate surface modification for adding novel surface/interfacial characteristics to the TiO 2 and VACNT hybrids, [14] and allow the constituent nanotube devices to be collectively addressed through a common substrate/electrode. [15] We previously prepared various vertically aligned conducting polymer-CNT coaxial nanowires by electrochemically depositing a concentric layer of an appropriate conducting polymer onto the individual aligned CNTs for advanced biosensing applications. [16] In this Communication,we report the use of VACNTs not only as the support for electrophoretic coating [17] with TiO 2 but also as the template for producing aligned TiO 2 nanotubes and nanomembranes. The resultant aligned TiO 2 -VACNT coaxial nanowires, TiO 2 nanotubes, and TiO 2 nanomembranes were demonstrated to possess novel photocurrent responses and photoinduced electron-transfer properties.In a typical experiment, we prepared VACNTs by pyrolyzing iron(II) phthalocyanine (FePc) on a Si substrate according to our published procedures. [18,19] For electrophoresis, aSi-supported VACNT film thus produced was used as the cathode and a graphite rod as the anode. Both electrodes were immersed...

Mechanical flexibility of electronic devices has attracted much attention from research due to the great demand in practical applications and rich commercial value. Integration of functional oxide materials in flexible polymer materials has proven an effective way to achieve flexibility of functional electronic devices. However, the chemical and mechanical incompatibilities at the interfaces of dissimilar materials make it still a big challenge to synthesize high-quality single-crystalline oxide thin film directly on flexible polymer substrates. This study reports an improved method that is employed to successfully transfer a centimeter-scaled single-crystalline LiFe O thin film on polyimide substrate. Structural characterizations show that the transferred films have essentially no difference in comparison with the as-grown films with respect to the microstructure. In particular, the transferred LiFe O films exhibit excellent magnetic properties under various mechanical bending statuses and show excellent fatigue properties during the bending cycle tests. These results demonstrate that the improved transfer method provides an effective way to compose single-crystalline functional oxide thin films onto flexible substrates for applications in flexible and wearable electronics.

A one-step growth of triangular silver nanoplates on a large scale is developed by a coordination-based kinetically controlled seeded growth method, with their edge length precisely tuned from 150 nm to 1.5 μm, and surface plasmon resonance extends to full near-infrared.